Neolacto series of glycolipids are expressed in the cortex only during embryonic development but disappear post-natally. These glycolipids however, continue to express themselves in cerebellum and peripheral nervous system (PNS) even in the adulthood. The major goal of this project is to determine the physiological significance of these glycolipids in the processes of cellular differentiation, cell-adhesion, plasticity and regeneration. Four specific aims are described: (1) To understand the regulation of their expression at the enzymic level (2) To evaluate if these glycolipids are involved in regeneration and remyelination processes of PNS, after nerve injury (3) To determine their precise cellular and subcellular localization in situ by light and electron microscopic studies, with the use of monoclonal antibodies and neurological mutants (4) To determine their role in cellular interaction using in vitro model systems. The studies should generate valuable information on the role of these glycolipids in cellular proliferation and migration during development of the embryonic cortex. Their possible role in plastic processes in cerebellum, and regenerative processes in PNS are being considered and evaluated.